Proxima Ovation 846 VGA problem

Hi out there,

at first I'm German and so my English is not as well as other people here. ;-)
I'm active in the DIY-Community.de but not here.
(of course because of the other language)

So my problem is:
I have a working Ovation 846. It is good but I have a problem with the VGA-Connector. S-Video works good but I wanted to make a Parallel-Port/VGA-Adapter to connect with Graphic Card.
So I did yesterday.
I was wondering why there is no Pin 15-Cable inside the VGA-Cable. I thought it should be connected with Pin 24 of the parallelport-Connector?!

Like I saw at this pic:


But then I thought it is not very important. Am I right?

Ok then I put al together and my Radeon-graphic card recognized the LCD-panel right. So I gave signal on it. The panel also recognized that there is a signal and the test-picture disappeared and a black screen was seen.
But WHY was it black? There was no image of my screen, only black.
I tried many things like changing the frequency and resolution of the signal. But nothing helped?!

So does anyone have an idea? I would be very glad if someone knew the answer of that problem.

Ok and an other problem on my S-Video picture is that the picture at this signal looks "disturbed". Is that only because of the S-Video-signal. So that it isn't better in quality or is there something wrong? I don't know how to say that, but the image looks "noisy".

I thank you for any ideas ... ;-)
please help